I have had dealings with managers at many TOCs, and XC is the only one where the atmosphere was grim even when around stakeholders from outside the company. Expressing an interest at working for XC is likely to raise eyebrows amongst railway colleagues. Looking at who has been recruited for the HQ staff over the last few years also tells its own story.
Quite aside from problems with the management, you also have to consider the morale issues resulting from the challenges facing the organisation. The unique operating position - 11 traincrew depots across 2170 route kilometres (third only to Northern and ScotRail who both operate within smaller areas). A fleet which is totally unsuitable for the demands on their network and has been for more than twenty years. The worst cancellation rate in the country. Punctuality only worsted by Avanti and Grand Central.
All this in a TOC which comes from a long line of neglect. From slightly peripheral inter-company through coaches and joint services pre-war, post-war into a growing service under a joint management committee but a lower-priority service shared between multiple regions, then a junior partner in the InterCity Midland Mainline / CrossCountry subsector, then an even more junior partner under Virgin, then into the more distinct but still stunted TOC that survives to this day.
When the only fixes to the fundamental problems facing XC are dependent on the thus-far disinterested Treasury and DfT, it's easy to see why staff morale is so poor.